Sound amplifier



Jan. 21, 1930. A. E. BRANDSTROM 1,744,101

SOUND AMPLIFIER Filed Sept. 12, 1928 n .r I

I'IIIIIIIIIIII Patented Jan. 21, 1930 UNITED STATES ARVID EMANUEL BRANDSTROM, 0F MILW'AUKEE, WISCONSIN SOUND AMPLIFIER Application filed September 12, 1928. Serial No. 305,449.

This invention relates to improvements in sound amplifiers and its object is to provide a device of this type that is adapted for use on combination radio and phonograph sets. One object is to provide means for interchangeably associating the amplifier operatively with either the radio or the phonograph.

With the foregoing and other objects in view the invention consists in the combination and arrangement of parts to be hereinafter fully described, pointed out in the appended claims and illustrated in the accompanying drawing which forms a part of this application for patent and in which- Fig. 1 is a vertical sectional view through the amplifier.

Fig. 2 is a view of the amplifier in front ele Vation.

Fig. 3 is a fragmentary sectional view in elevation.

Fig. 4 is a view of Fig. 3 with the relatively adjustable parts in an altered position.

Fig. 5 is a cross section on line 55 of Fig. 3.

Like reference characters denote corresponding parts throughout the several views.

The amplifier comprises a hollow truncated pyramidal body having a plurality of in terior partitions whereby it is divided into sound passageways, an exterior communieating passageway leading thereinto from a radio and from a phonograph said exterior passageway being provided with an adjustable baiile whereby the passageway to the radio is cut oil and the passageway to the phonograph leftunobstructed or vice versa, manually operable means for effecting the adjustment of said battle being provided.

The reference numeral 1 denotes a hollow truncated pyramidal body which in this instance is octagonal in cross section although not essentially so.

It is formed with four connected longitudinally extending partitions 2 forming a parallelogram the inner termination of which is spaced inwardly from the smaller end of the body 1, the corners of said parallelogram being connected by partitions 3 to the body, said parallelogram being formed with a transverse partition 4 the central portion of one face of which is shaped to form the integral cone 5.

Extending in both direct-ions from the smaller end 6 of the body andthrongh the same and at right angles thereto is the elongated shell 7, the end 8 thereof being closed and the opposite or inner end being open and receiving the apex of the cone 5 centrally of its open end, the exterior periphery of the inner end of said shell being rounded and spaced inwardly from the walls 2 of the parallelogram, the inner periphery of the closed end being formed with the rounded recessed portions 9, 9 separated by the centrally disposed transversely extending ridge 10, a pipe 11 extending transversely through the sides of the exterior portion of the shell 7 and being provided with spaced collars 12 that abut the shell to prevent longitudinal movement of said pipe which member within the shell is formed with a perforation or cutout portion 13 in the plane of the ridge 10, the pipe material being bent or flared somewhat about said perforation to form the lips 14L disposed upon opposite sides of said ridge 10 and spaced away therefrom.

Extending longitudinally and centrally of the shell 7 is the wedge shaped partition 15, the tapered inner end of which is spaced a short distance from the apex of the cone 5, the lateral edges of said wedge being secured to the lateral walls of the shell, the large end of said partition being formed with an arcuate recess and engaging the pipe 11, said wedge being spaced inwardly from the top and bottom walls of the shell 7 Slidably mounted in the pipe 11 at its cut out portion and adapted to serve as a closure for the pipe at either side of its out out portion is the baffle 16 engaged by one end of the rod 17 that extends through one side wall of the elongated shell 7 whereby said baflie is moved from side to side of said cut out portion, opposite positions of said member 16 being shown in Figs. 3 and 4, said rod 17 passing through one collar 12 and through a guide 18 secured to the said pipe.

One end of the pipe 11 runs to the sound box of the phonograph and the opposite end to the radio (neither the phonograph nor the radio being shown) and when one of said members is to be heard the baffle is moved to a position in the pipe 11 to cut off the sound passageway leading to the other member, by means of the rod 17.

The sound coming through the pipe 11, which is a sound passageway, from either side strikes the baffle 16 and passes about the ridge 10 and upon opposite sides of the wedge 15 through the elongated shell 7, upon opposite sides of the cone 5 and is deflected by the partition & and passes about the exterior periphery of the shell 7 and strikes the inner face of the smaller end of the body 1 and then out through the passageways formed by the inner periphery of the body 1 and the exterior of the walls 2 of the parallelogram and by the partitions 3. Should the radio and phonograph be in operation at the same time either could be heard selectively by merely positioning the baffle 16 in the pipe to cut oh the instrument not desired.

What is claimed is 1. In a sound amplifier, a hollow truncated pyramidal body, connected partitions extending longitudinally thereof and forming a parallelogram, partitions connecting the corners of said parallelogram with said pyramidal body, a partition in said parallelogram, a cone formed centrally of said partition, an elongated shell extending through the smaller and closed end of said body and receiving the apex of said cone in its inner end, the outer end'of said shell being closed, a ridge formed centrally of the inner periphery of the closed end of said shell, a wedge partition extending longitudinally of said shell, the pointed end thereof being spaced from said cone, the larger end thereof being recessed, a pipe received in the recess in said wedge and extending transversely of said shell and formed with a cut out portion in the plane of said ridge, and means for closing said pipe at either side of its out out portion.

2. In a sound ampllfier, a hollow truncated versely of said shell and formed with a cut out portion in the plane of said ridge, and means for closing said pipe at either side of its out out portion.

3. In a sound amplifier, a hollow body comprising a plurality of intercommunicating sound passageways, an elongated shell associated therewith and comprising a plurality of intercommunicating passageways, a pipe received in said shell and formed with a cut out portion, a baffle mounted for movement in said pipe whereby the same may be closed at either end of said out out portion, and a hand rod for actuating said battle.

In testimony that I claim the foregoing as my own I have hereto affixed mysignature.

ARVID EMANUEL BRANDSTROM.

pyramidal body, connected partitions extending longitudinally thereof and spaced inwardly therefrom and forming a parallelogram, partitions connecting the corners of said parallelogram with said pyramidal body, a transverse partition in said parallelogram, a cone formed centrally of said partition, anelongated shell extending through the smaller and closed end of said body and receiving the apex of said cone in its inner end, the outer end of saidshell being closed, a ridge formed centrally of the inner periphery of the closed end of said shell, a wedge shaped partition extending longitudinally and centrally of said shell, the pointed end thereof being spaced from said cone, the larger end being recessed, a pipe received in the recess in said wedge and extending trans- 

